Japanese Utility Model Patent Laid-Open (Patent document 1) describes a wall-hung one-piece toilet. Because the mounting of such wall-hung flush toilets away from floor surfaces yields the advantage of good floor cleanability, such toilets are in ever wider use.
A flush toilet in which the toilet bowl is cleaned by a swirl flow of flush water issued from an upper portion of the bowl portion is set forth in Japanese Patent Laid-Open No. 2004-100307 (Patent Document 2). Since such flush toilets, in which the bowl surface is cleaned by a swirl flow, do not have a box rim or the like causing flush water to be issued downward from the edge of the bowl portion, their shape is simple and cleanability of the bowl portion superior, hence they are widely used.
Patent Document 1
Japanese Utility Model Patent Laid-Open No. H03-128774
Patent Document 2
Japanese Patent Laid-Open No. 2004-100307